Load transfer device for roadways



Jan. 1l, 1938. B. JOHNSON LOAD TRANSFER DEVICE FOR ROADWAYS Filed April15, 1957 2,1 14 aq Z l www NTE STATES PATENT OFFICE Dow-Weld Company,Inc.,

Maryland a corporation of Application April 15, 1937, Serial N0. 137,114

4 Claims.

This invention relates to joint forming means to be used in roadways,pavements and the like, and more particularly to a load-transfer devicefor concrete roadways for permitting the con- 5 crete slabs forming theroadway to expand and contract.

One of the objects of the invention is the construction of a dowelassembly to be used in conjunction with the expansion joint or expansionmaterial in a concrete roadway, said assembly serving to hold its dowelsparallel to each other and likewise parallel to the iinished grade.

Another purpose is the formation of a dowel assembly to be used inconjunction with an ex- 10 pansion joint or expansion material in aconcrete roadway, said assembly having an angle member forming acontinuous bearing support for the joint throughout its entire lengthand serving to prevent the overturning or depression ofthe joint.

Still a further aim is the building of a dowel assembly of the characterabove specified and in which the dowels of the assembly are rigidlyfixed with respect to each other permitting the deposition of concreteover the joint and dowels and yet holding the joint in perfect alignmentat all times.

Other aims and objects will be apparent to those skilled in the art fromthe description of the invention hereinafter appearing when read inconjunction with the appended drawing forming a part hereof to whichreference is now made in which:-

Fig. 1 is a perspective View of the novel dowel assembly prior to itsinsertion in a concrete pavement or roadway and showing the manner inwhich the dowels are connected to each other and to an angularsupporting bearing member.

Fig. 2 is a View partly in section and partly in elevation, showing themanner of mounting the dowel assembly in a concrete roadway and itsrelationship to an expansion joint normally positioned between adjacentslabs of the roadway.

Fig. 3 is an enlarged perspective View, partly broken away, showing therelationship between the expansion joint and its dowel assembly.

Fig. 4 is a view similar to that oi- Figure 2, but showing a modifiedtype of dowel bar.

Referring first to Figures 1 to 3, inclusive, the

dowel assembly isgenerally designated as A and is shown as comprising anelongated supporting member It, in the form of an angle iron, said angleiron or member having a horizontal portion II and a Vertical portion I2at right angles thereto. By the use of the term horizontal and verticalto describe the portions II and I2 respectively, of said angle ironmember I0, it will be understood that this defines the respectiveoperative positions of these portions when the assembly A is set in aroadway for use in conjunc- 5 tion with an expansion joint, indicated onthe drawing as E.

The reference numeral I3 designates a series of similar dowel pins orbars, each characterized by a horizontal section I4 and a downwardly ex-10 tending curved section I5, projecting from said horizontal sectionI4. It is preferred to construct each dowel I3 of a single piece ofthreequarter inch metal of circular cross-section, although variousother thicknesses may be eml5 ployed. A transverse bar I6 is welded asat l1 to al1 of the dowel bars I3 to hold the latter in alignment inequidistantly spaced parallel vertical planes. The lowermost portion orend of the hooked-shaped or curved section I5 of each bar 20 I3 isrigidly connected, preferably by welding, as at points I8 and I9, to thehorizontal and vertical portions of the angle member I Il. By referenceto Fig. 2 of the drawing it will be seen that the transverse bar I6 isin spaced relation to the 5 vertical portion I 2 of the angle member I0and in the same vertical plane therewith. The purpose of thisconstruction will be shortly described.

In the building of a roadway the sub-grade G is first prepared toprovide a suitable foundation, 30 and the dowel assembly A is thenpositioned thereon with the vertical portion I2 of the angle iron ofsaid assembly normal to the upper surface thereof. The expansion joint Eis provided with spaced apertures 20 through which the hori- 35 zontalsections I4 of the dowels I3 pass, as will be seen by reference to Fig.3 of the drawing. Loosely positioned over the outer end of each of saidsections I 4 is a tubular expansion sleeve 2l for a purpose to beshortly described. 40

By virtue of the fact that the rod I6 is in the same vertical plane asthe portion I2 of the angle iron IIl, the expansion joint E is properlypositioned in a vertical plane when it is moved into contact with oneface I2 of the angle iron II) and with the horizontal rod I6, as will beseen from an inspection of Fig. 2 of the drawing. The expansion joint Eand the entire dowel assembly A are preferably held in this position byany suitable means while the concrete C is poured to form concrete slabson both sides of the joint E. The tubular expansion sleeve 2l, rigidlyheld in position by the concrete, loosely receives the free end of thesection I4 of each dowel I3 to 55 allow expansion and contractionthereof. This will also be seen by reference to Fig. 2 of the drawing.

In the modified form of the invention shown in Fig. 4 of the drawing,the dowel bar 23 is characterized by a horizontal portion 24 and avertical portion 25 at right angles to said horizontal portion andintermediate the ends thereof, forming in effect a T-shaped dowel. Thevertical portion 25 is welded to the angle member I0 in a manner similarto that ydescribed with reference to the preferred embodiment of theinvention shown in Figs. l `to 3 inclusive. It will also be understoodthat there are a plurality of T-shaped dowels 23 corresponding to dowelsI3, a rod or bar I5 welded to said dowels 23, and the principles of theinvention and other details of construction are the same in both thepreferred embodiment of the invention and in the modied form of Figure4.

From the foregoing description, it will now be apparent that the dowelswill always be held parallel to each other and to the finished grade;that vthe angle member forms a continuous support or prop for theexpansion joint and serves to prevent the overturning thereof. Also itwill be understood that in lieu of a preformed joint, a joint may bebuilt up to extend above the subgrade and that the dowel assemblyservesto maintain the joint normal to the roadway bed and grade. Whileit is preferred to weldthe dowels to the angle member other forms ofconnecting the same may be employed.

Obviously the invention is susceptible to more or less mcdication thanwhat has been shown and described, and desirable changes may suggestthemselves to those skilled in the art without departing from the spiritof the invention. It is contemplated to cover all such modification andto be limited in this respect only as may be necessary by the claimshereto appended.

I claim:-

1. A load-transfer device for roadways comprising a supporting memberhaving horizontal and vertical flanges, a plurality of dowels positionedat spaced intervals extending above said member and transverselythereof, said dowels each having a vertical extension rigidly connectedto said member.

2. A load-transfer device for roadways comprising a supporting memberhaving horizontal and vertical flanges, a plurality of dowels positionedat spaced intervals extending above said member and transverselythereof, each of said dowels having an integral vertical extensionwelded to the horizontal and vertical anges of said supporting member.

3. A load-transfer device for roadways comprising a supporting memberhaving horizontal and vertical flanges, a plurality of dowels positionedat spaced intervals extending above said member and transverselythereof, each of said dowels having an integral vertical extensionwelded to the horizontal and vertical flanges of said supporting member,and means connected to all of said dowels for maintaining same and saidsupporting member as a rigid unit.

4. A load-transfer device for roadways cornprising an angle memberhaving horizontal and vertical flanges, a plurality of dowels having ahorizontal portion and a downwardly extending vertical portion at oneend thereof, said horizontal portions extending at spaced intervals inIa single horizontal plane above and transversely 1.

of said angle member, said vertical portions being rigidly secured tosaid flanges, and a rod secured to all of the horizontal portions ofsaid dowels.

LOUIS B. JOHNSON.

